@manawyrm @q let me guess: Those were used for #Osmocom / #OpenGSM devs that tended to use #ChaosCommunicationCongress as testing grounds for their Software...

Sadly the bands have been allocated and AFAIK all regular multi-band #GSM bands have veen allocated and the only Sub - 700MHz bands unused are extremely uncommon (GSM-400 for example) and @BNetzA won't issue even experimental useage licenses for events in said bands...